Morgan AS, Zeitlin J, Källén K, et al. - Despite controlling for background factors, differences in survival and morbidity outcomes for extremely preterm births are observed. There was no clear link found between early mortality and subsequent morbidity trends.

• EXPRESS (Sweden, 2004–07), EPICure-2 (England, 2006) and EPIPAGE-2 (France, 2011) cohort data were harmonised.

• At 22–23 weeks’ GA, 112-day survival was 28.2%, 10.8% and 0.5% for 769 EXPRESS, 2310 EPICure-2 and 1359 EPIPAGE-2 foetuses; 68.5%, 40.0% and 23.6% for 24 weeks; 80.5%, 64.8% and 56.9% at 25 weeks; and 86.6%, 77.1% and 74.4% for 26 weeks.

• EPIPAGE-2 death rates were highest before 1 day at 22–23 and 24 weeks GA.

• Survival varied before 28 days at 25 weeks; changes at 26 weeks were minor.

• Cox analyses were compatible with the Kaplan-Meier analyses. Morbidity variations were not strongly connected with survival.